There are many known devices for remotely disengaging the operation of a vehicle, which devices are widely used in numerous commercial and industrial settings, and which vary greatly in terms of their function and ability. Typically, remote shutoff devices, of the kind generally relevant as background to the present invention, are used in connection with vehicles which require the assistance of a guide or “spotter” during operation in environments where other workers are moving about, as well as in an industrial setting such as a production or assembly line.
Within environments where vehicles or machines operate in close proximity to individuals and/or property, there is some risk of injury to those individuals or property. As a result, conventional safety measures within these environments include the use of two-way radios, for communication between the operator of a vehicle and a person located near the moving vehicle, commonly referred to as a “spotter”. It is the spotter's job to warn the vehicle operator of any impending likelihood of injury or collision.
While the two-way radio serves to significantly reduce the likelihood of injury to surrounding persons and/or property, there are occasions where, despite use of the two-way radio, there is a risk of injury occurring as a result of the machine operator being unable to hear the radio communication. The machine operator may be unable to hear the radio due to ambient noise, or injury may occur due to the inherent delay between a remote spotter noticing a problem developing, the remote spotter sending a stop request to the vehicle operator, the vehicle operator receiving the stop request, and the actual stopping of the machine.
In other situations, a machine operator, repairman or observer may be required to move about in the immediate area of a conveyor or stationary machine having moving parts. The operator may need a remotely controllable shutoff and/or warning device, to quickly warn others or interrupt operation of the machine, in case a hazardous situation arises.
In an attempt to reduce the occurrence of injury to persons and property, remote shutoff devices were developed to immobilize a moving movable machine. Several variants of remote shutoff devices are illustrated in U.S. Pat. Nos. 4,628,306, 5,805,057, 6,072,248, and 6,285,860.
Root, U.S. Pat. No. 4,628,306, entitled, “Remote Control System For Automated Equipment,” discloses a radio-frequency control system for a robotic device. The system of Root provides both a “soft stop” or “cycle hold” control and a “hard stop” function. The system of Root is provided for a technician who may be repairing the robotic device with the normal proximity switches deactivated for the repair operation.
Eslaminovin, U.S. Pat. No. 5,805,057, entitled, “Remote Vehicle Disabling And Distress Indicator System,” discloses a remote control system for use with motor vehicles. The system of Eslaminovin is operated using a remote telephone, which sends a signal to a modular telephone stored in the vehicle. A distress signal sent to the modular telephone will deactivate the vehicle, either by deactivating the ignition coil or by closing a fuel shutoff valve.
Muise et al., U.S. Pat. No. 6,072,248, entitled, “Method of and System for Externally and Remotely Disabling Stolen or Unauthorized Operated Vehicles by Pursuing Police and the Like,” discloses a system in which an anti-theft receiver is provided in a vehicle, and this receiver may receive signals from a pursuing police car, at such time as the vehicle is being operated by an unauthorized driver. The receiver of Muise et al. is capable of controlling fuel flow to the engine to provide a successive reduction in fuel supply, finally shutting off all fuel flow thereto and stopping the car.
Szarka et al., U.S. Pat. No. 6,285,860, entitled, “Construction Equipment Lockout System With Emergency Shutdown,” discloses a system which can be used with a movable robotic machine such as a directional drill. In particular, the control system of Szarka et al. provides a lockout function which inhibits one or more functions of the equipment being operated, under predetermined operating conditions. The functions may include power to the hydraulic unit, engine power, power wrench operation, etc. The equipment lockout control system of Szarka et al. includes at least one radio receiver that includes an equipment inhibitor device for disabling a function of the equipment. A portable transmitter that is operable by an operator is located on or near the operator. The portable transmitter includes circuitry for generating a continuous radio signal that is receivable by the receiver. Upon detecting an interruption in the continuous radio signal, the receiver renders the equipment inhibitor effective, and disables a function of the equipment.
While the aforementioned inventions provide a variety of remote shutoff devices to temporarily render machinery inoperable, a need still exists in the art for a remote shutoff device which enables a machine operator, observer or “spotter” to temporarily disable the vehicle or other machine, in the event such action is necessary to protect persons or property, and which requires a manual reset of the machine, prior to rendering the machine operable once again.